title: Life cycle assessment of a parabolic trough concentrating solar power plant and the impacts of key design alternatives.
abstract: Climate change and water scarcity are important issues for today's power sector. To inform capacity expansion decisions, hybrid life cycle assessment is used to evaluate a reference design of a parabolic trough concentrating solar power (CSP) facility located in Daggett, CA, along four sustainability metrics: life cycle (LC) greenhouse gas (GHG) emissions, water consumption, cumulative energy demand (CED), and energy payback time (EPBT). This wet-cooled, 103 MW plant utilizes mined nitrates salts in its two-tank, thermal energy storage (TES) system. Design alternatives of dry-cooling, a thermocline TES, and synthetically derived nitrate salt are evaluated. During its LC, the reference CSP plant is estimated to emit 26 g of CO(2eq) per kWh, consume 4.7 L/kWh of water, and demand 0.40 MJ(eq)/kWh of energy, resulting in an EPBT of approximately 1 year. The dry-cooled alternative is estimated to reduce LC water consumption by 77% but increase LC GHG emissions and CED by 8%. Synthetic nitrate salts may increase LC GHG emissions by 52% compared to mined. Switching from two-tank to thermocline TES configuration reduces LC GHG emissions, most significantly for plants using synthetically derived nitrate salts. CSP can significantly reduce GHG emissions compared to fossil-fueled generation; however, dry-cooling may be required in many locations to minimize water consumption.
authors.affiliation: National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, Colorado 80401-3393, United States.
authors.forename: John J
authors.initials: JJ
authors.lastname: Burkhardt
authors.forename: Garvin A
authors.initials: GA
authors.lastname: Heath
authors.forename: Craig S
authors.initials: CS
authors.lastname: Turchi
mesh_terms: D000397:Air Pollution / Q000706:statistics & numerical data; D058572:Carbon Footprint / Q000706:statistics & numerical data; D003247:Conservation of Natural Resources / Q000379:methods*; D004777:Environment; D005160:Facility Design and Construction; D011210:Power Plants / Q000295:instrumentation*; D012993:Solar Energy